Chandigarh, Oct 22: Cancer cases associated with obesity are rising not only among younger adults but also in older populations worldwide, according to a new global study.
Researchers from The Institute of Cancer Research and Imperial College London analysed data from 42 countries across Asia, Europe, Africa, North and South America, and Australasia, drawn from the International Agency for Research on Cancer’s ‘GLOBOCAN’ database. The findings, published in the Annals of Internal Medicine, examined annual cancer incidence between 2003 and 2017.
The study found five obesity-related cancers—thyroid, breast, kidney, endometrial, and blood (leukaemia)—increasing in adults aged 20–49 as well as those 50 and older. “Cancer incidence rates increased for several cancer types in many of the countries studied; however, other than colorectal cancer, these increases occurred in both younger and older adults,” the authors wrote.
Rates of cancer among younger adults rose in over three-fourths of the countries studied for thyroid, breast, colorectal, kidney, endometrial cancers, and leukaemia. Colorectal cancer was an exception, with younger adults experiencing a sharper rise in nearly 70 per cent of countries. The researchers suggested this could be due to exposure to new cancer-causing agents or more effective screening among older adults.
For other cancers—liver, oral, oesophageal, and stomach—the incidence among younger adults remained lower than in older populations in more than half of the countries analysed.
“Endometrial and kidney cancers are most strongly associated with obesity, and the rising trends across age groups highlight that changes in exposure leading to higher cancer rates are not limited to younger adults,” the team noted. They cautioned that studies focusing solely on younger adults may need reconsideration in light of these findings.
